<script>
    let arr = [1, 2]
    let successArr = []
    for (let k of arr.keys()) {
        let r = Reflect.deleteProperty(arr, k)
        successArr.push(r)
    }

    let arr2 = Array(3)

    console.log(successArr, arr, arr2)


    for (let k of arr) {
        console.log(k)
    }
</script>